The present invention relates to the submerged arc welding of cylindrical metallic workpieces to apply a metallic facing thereon.
It is conventional to provide cylindrical metallic workpieces with a facing of a harder metal for various reasons, such as, for example, to make the workpiece stronger or more resistant to corrosion. For instance, a cylinder formed of soft steel may be provided with a reinforcing facing of harder steel.
The facing is typically applied by a conventional submerged arc welding process in which an arc is generated across the workpiece and a consumable electrode formed of the facing material. The heat generated by the arc melts the surface of the workpiece and the electrode tip, whereupon a layer of the electrode material is deposited onto the workpiece. The workpiece is rotated about its own axis relative to the electrode, and the electrode tip is kept submerged within a covering of granulated flux to resist oxidation. The flux is contained within a flux retainer which rests immovably upon the workpiece as the latter rotates.
It has been heretofore proposed to form a flux retainer in the form of a box-shaped framework having four wheels at the corners, the wheels riding upon the workpiece as the latter revolves. Metal brushes are carried by the framework and are arranged parallel to the workpiece axis in wiping relationship to the surface of the workpiece to resist escape of flux along the end of the retainer. The retainer is connected to the electrode head and thus remains stationary as the workpiece revolves. A tube extends from a source of granulated flux and includes a discharge outlet communicating with the confines of the flux retainer to replenish flux which may leak from the sides of the retainer.
When using a flux retainer of the type described above, it has been necessary to provide different retainers for various workpiece diameters in order to properly locate the brushes against the workpiece surface. Furthermore, the brushes have heretofore been formed of metals such as steel and aluminum. These brushes, which are characterized by a relatively low coefficient of thermal conductivity, have not exhibited a satisfactory life span before being decimated by the high temperatures which are encountered during the welding process.
It is, therefore, an object of the present invention to provide a novel retainer for granular flux for use in a submerged arc-welding process.
An additional object is to provide such a flux retainer which is adapted for use with cylindrical workpieces of a wide variety of diameters.
A further object is to provide such a flux retainer with flux-confining brushes having a longer life span.